diff --git a/api/controllers/console/app/workflow.py b/api/controllers/console/app/workflow.py
index de85636f5e..ea0b918508 100644
--- a/api/controllers/console/app/workflow.py
+++ b/api/controllers/console/app/workflow.py
@@ -12,6 +12,7 @@ from werkzeug.exceptions import Forbidden, InternalServerError, NotFound
 import services
 from controllers.console import console_ns
 from controllers.console.app.error import ConversationCompletedError, DraftWorkflowNotExist, DraftWorkflowNotSync
+from controllers.console.app.online_user import WORKFLOW_ONLINE_USERS_PREFIX
 from controllers.console.app.wraps import get_app_model
 from controllers.console.wraps import account_initialization_required, edit_permission_required, setup_required
 from controllers.web.error import InvokeRateLimitError as InvokeRateLimitHttpError